The free world is the new continent in cyberspace that we have built so we can live here in freedom. It's impossible to live in freedom in the old world of cyberspace, where every program has its feudal lord that bullies and mistreats the users. So, to live in freedom we have to build a new continent. Because this is a virtual continent, it has room for everyone, and there are no immigration restrictions. - Richard Stallman -

CentOS is a community-supported, mainly free software operating system based on Red Hat Enterprise Linux (RHEL). It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution. CentOS stands for Community ENTerprise Operating System.

CentOS is the most popular Linux distribution for web servers with almost 30% of all Linux servers using it.

Structure.

Red Hat Enterprise Linux is available only through a paid subscription service that provides access to software updates and varying levels of technical support. The product is largely composed of software packages distributed under either an open source or a free software license and the source code for these packages is made public by Red Hat.

CentOS developers use Red Hat's source code to create a final product very similar to Red Hat Enterprise Linux. Red Hat's branding and logos are changed because Red Hat does not allow them to be redistributed.

CentOS is available free of charge. Technical support is primarily provided by the community via official mailing lists, web forums, and chat rooms. The project is not affiliated with Red Hat and thus receives no financial or logistical support from the company; instead, the CentOS Project relies on donations from users and organizational sponsors.

Updates:

Karanbir Singh has announced the release of CentOS 6.0 "Live", a set of installable live CD and DVD images based on Red Hat Enterprise Linux 6.0: "We are pleased to announce the immediate availability of CentOS 6.0 live CD for i386 and x86_64 architectures. The CentOS 6.0 live CD is meant to be a Linux environment suited to be run directly from either CD media or USB storage devices. Due to space constraints, it was not possible to include all the traditional desktop applications on the live CD. You can though enjoy a GNOME basic desktop, view and modify pictures with gThumb and the GIMP, browse the web with Firefox, send emails with Thunderbird and connect to your favorite instant messaging network with Pidgin."

CentOS version numbers have two parts, a major version and a minor version. The major and minor version numbers respectively correspond to the major version and update set of Red Hat Enterprise Linux from which the source packages used to build CentOS are taken. For example, CentOS 4.4 is built from the source packages from Red Hat Enterprise Linux 4 update 4.

To meet that overall goal, we strive to achieve:

* easy maintenance
* self hosting distribution (one that can build on itself)
* suitability for long term use in production environments
* friendly environment for users and package maintainers
* long-term support of the core
* active development
* community infrastructure
* open management
* open business model
* commercial support - offered by partner vendors

CentOS uses the original sources whenever possible. Under normal circumstances CentOS will NOT add patches to original upstream source packages.

The vast majority of changes made will be made to comply with the upstream vendor's re-distribution policies concerning trademarked names or logos. Any other changes made will be spelled out in the Release Notes for the individual CentOS product.